[docs][base-ui] Revise the structure of the Component docs

[samuelsycamore]

In the current version of the Base UI docs, the headers are structured like this:

## Introduction
## Component
### Usage
### Basics
### Anatomy
### Custom structure
## Hook
### etc.

Preview: https://deploy-preview-38529--material-ui.netlify.app/base-ui/react-switch/

In practice, there's a lot of overlap between the Introduction, Usage, and Basics sections, and some of the docs have redundant content repeated in each—particularly since we added the Intro playgrounds.

This PR:

• condenses Usage and Basics in to one section called Usage
• removes most of the boilerplate Basics code (leaving only the import, as we've done in the Joy UI docs)
• removes Usage/Basics content where it's just repeating the Introduction

I also couldn't resist doing some copyediting, mostly to the Autocomplete page.

Before:

After:

Right now this PR only involves a few of the pages, because I want to make sure we agree on the updated format before applying it to all others. I tried to take a sample of several different kinds of pages to see how the new format works. There may be other kinks to work out in the next pass, but I think this is good way to proceed.

[mui-bot]

Netlify deploy preview

• docs/data/base/components/autocomplete/autocomplete.md
• docs/data/base/components/slider/slider.md
• docs/data/base/components/switch/switch.md
• docs/data/base/components/tabs/tabs.md

Bundle size report

No bundle size changes (Toolpad)
No bundle size changes

Generated by 🚫 dangerJS against 998e891

[danilo-leal]

Really like this new structure! Makes a ton of sense to me 🤙

[samuelsycamore]

Ah shoot @siriwatknp I should have marked this as a "DO NOT MERGE"—I'd like to wait to apply the updated format to all pages before this PR goes out. Can we revert it?

[oliviertassinari]

I would be in favor of always having the author merge PRs, unless the changes are obvious or the PR got forgotten. Two other cases: #38393, #38241 (as I understood it, Rich was a bit surprised) where I feel merging wasn't ideal.

[siriwatknp]

Ah shoot @siriwatknp I should have marked this as a "DO NOT MERGE"—I'd like to wait to apply the updated format to all pages before this PR goes out. Can we revert it?

Oops! sorry.

[samuelsycamore]

No worries @siriwatknp! It's not a big deal to have this merged early—I'm sure we'll still do a couple more drafts of these docs before the stable release.